Notes on repair. I did swap in the new MAF before I caught the boost pipe fitment problem. Tugging off the MAF I pulled off the air cleaner induction pipe off the turbo way too easily, and sure enough I did not have a good fitment on that connection.

Put the PCV purge hose on first before connecting to the turbo...on the 1999 there is a lot of tension on the PCV hose. Make sure the PCV clamp grabs the hose and not the plastic ridge on the induction hose

Make sure clamp isnt compressing plastic boss instead of soft pipe

I used SS clamps ( worm drive) and got them nice and tight. They do boost up to pressure, of course

I put the old MAF back in and now have a known to be good spare Bosch MAF